Joined: Mar 2015
Posts: 20
Likes: 0
From: Chicago
Bikes: 2012 Giant Defy Composite, 1989 Paramount OS, 50th Anniversary Paramount Track, 1986 Paramount Road, 1981 Superior, late eighties Kestrel MX-Z, 1974 Viscount Aerospace, circa 1972 Gitane Tour de France, 2011 Dahon folder
Thank you all for your input. I am now in the hunt for a 1" threadless set or just top set, because:
1) Paying a machine shop to lathe it out properly is more costly than a new one.
2) Doing it myself, however carefully, is likely to wreck the A9 adjustable cup, making it worthless in either application.
3) I already own a threadless carbon / aluminum fork, and using a threaded one, with quill stem, puts the project overweight and over budget. (even though I'd like to use the branded OEM stem, it's just an anchor)
4) I will not thread an aluminum steerer, designed and installed for a threadless application. A loose, creaky headset is annoying, a cracked, broken or otherwise compromised steerer is potentially fatal.
Great help, everyone, thanks again.